1. Field of the Invention
The invention relates to a device for producing a rotating flow in a flow duct which comprises a flue-gas outlet of an incineration plant, in particular of a garbage incineration plant.
2. Discussion of the Prior Art
Such devices are used in order to regulate by means of the injected media the composition of the flue-gas mixture conveyed through the flow duct of an incineration plant and the temperature and dwell time of the flue-gas mixture. However, the composition, temperature and dwell time are not only to be regulated but in particular are also to be evened out. In this way, optimum secondary combustion of the flue-gas mixture can be ensured and the desired, low emission values can be maintained. This necessitates complete intermixing of the flue-gas mixture. Attempts are made to achieve this complete intermixing by producing rotating flows in the flow duct by means of devices having appropriate nozzle arrangements.
U.S. Pat. No. 5,252,298, for example, discloses a device of the generic type. The nozzles arranged in a plane are oriented tangentially to an imaginary circle in the center of the flow duct, so that a rotating flow is produced in the flow duct. In a device disclosed by DE-A-19 648 639, the flow rate is controlled by means of nozzles arranged opposite one another in the flow duct in such a way that at least two flows rotating in opposition are obtained in the flow duct. The problem with these known rotating flows consists in the fact that a virtually vortex-free eye arises in the center of the flow, with the result that complete intermixing and thus uniform composition, temperature distribution and dwell time are not obtained.